Marine Weather and TidesLancaster, PA

Version 3.4

What's New / NOTES
3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.

Sunrise 7:07AM

Sunset 7:18PM

Monday March 19, 2018 10:22 PM EDT (02:22 UTC)

Moonrise 7:35AM

Moonset 8:37PM

Illumination 11%

NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.

ANZ500 853 Pm Edt Mon Mar 19 2018 Synopsis for the tidal potomac and md portion of the chesapeake bay.. Coastal low pressure will emerge and strengthen off the mid atlantic coast tonight into Tuesday. Another low pressure system will develop off the carolina coast Tuesday night, passing south of our region. High pressure will build in from the west Thursday and Friday. A small craft advisory will likely be needed for the waters Tuesday night through Thursday.

Synopsis
Big changes to our weather on the way as a storm system will
affect the area for the first day of spring tomorrow. The storm
will primarily affect the southern half of the area. It will
initially bring a mixture of rain and snow but by Tuesday night
and Wednesday primarily snow will fall and significant
accumulations are possible across southern pennsylvania. Cooler
than average temperatures will dominate the pattern through the
end of the week, with the next opportunity for precipitation
coming this weekend.

Near term until 6 am Tuesday morning
Near term in good shape with increasing clouds tonight. Latest
hrrr nam12 shows precip shield moving towards CWA in the pre
dawn hours. Latest href2 lags by a couple of hours, bringing
precip shield into laurels and south central mountains after
12z. Siding with the earlier hrrr nam12 at this time into the
laurels. Temperatures should be cold enough for snow across the
south, but QPF should be light enough to limit much in the way
of accumulation initially.

Short term 6 am Tuesday morning through 6 pm Tuesday
Complicated storm system with snow and potentially some mixed
precipitation across southern half of cwa. Initially the
temperature profile and intensities of the precip suggest snow
will have trouble sticking in valleys and banding will determine
where accums are more efficient. Higher elevations will see
more accumulating snow. Temperature profiles cool dynamically
and this has become more pronounced in the 18z and early look at
00z Tue nam12 run. This brings a better chance of accumulating
snow for valley locales as well. Snow will continue into
evening and Wednesday and winter storm watch remains in effect
for southern zones for the long duration of potential snow fall.

Kept the watch in place to allow mid shift opportunity to assess
latest numbers as we are approaching 12- and 24- hour warning
criteria and trend from 00z runs and cams will provide critical
information.

Besides the typical march complications with snow accumulations
(moderate to heavy snowfall rates needed to offset melting as
snow falls due to higher Sun angles), the duration nature of
this system will make achieving warning criteria difficult, with
only 30-40% probs of 6" or more in a 12 hour period in the watch
area currently, and 30-40% probs of 8" or more in a 12 hour
period from Tuesday morning through Wednesday afternoon. Latest
guidance from the 12z Mon cycle has ramped up QPF snow totals
over southern pa, but this may be in part due to an overzealous
nam package. The current 90th percentile snowfall for somerset
county is in the ridiculoso range (not to be mentioned here),

far beyond anything we are reasonably forecasting, so am hoping
that the addition of global model members into the pdf suite
will yield greater confidence and less spread probabilistically
for the overnight forecast tweaks.

Long term Tuesday night through Monday
By daybreak Wednesday the storm is expected to be reorganizing
off the mid atlantic before tracking off south of nantucket
island. The upper trough low will keep some light precip
lingering Tuesday night and Wednesday morning. An additional
coating of snow is possible as surface temperatures chill down
into the 20s in most areas Tuesday night.

By later Wednesday cool and drier air will begin filtering in.

Weak high pressure will keep us fair through Friday before the
next approach storm brings a chance of rain or snow Saturday
night and Sunday. This looks to be a clipper type way which will
move through the area quickly with high pressure following for
next Monday.

Aviation 02z Tuesday through Saturday
Vfr for into early morning hours. Patchy light rain and snow
will be possible by sunrise on Tuesday... Mainly along the
pa... Md border. Lower CIGS and snow for southern pa on tue
continuing into wed.

Outlook...

tue... Snow restrictions likely southern pa.

Tue night and wed... More snow at times. Restrictions at times.

Thu-fri... No sig wx expected.

Climate
The spring (vernal) equinox will be at 12:15 pm on Tuesday,
march 20. Sunrise in state college, pa will be 7:14 am and
sunset at 7:23 pm, for a total day length of just over 12
hours.

Weather Map and Satellite Images

(on/off) &nbspHelpWeather MapGOES Local Image of Mid-AtlanticEDITNOTE: East coast views moved to GEOS-16. They are experimental and not well supported by NOAA so they may not be correct so be warned. This change required redoing a large amount of the GOES code. If the image you are expecting is not showing, please let me know. You may need to use the EDIT function to update your location. target = "new">Link to Loop

Wind Forecast for State College, PA (22,6,7,8)

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